Ultra high efficiency catalyst for polymerizing olefins

ABSTRACT

Compositions consisting of the reaction product or complex resulting from the mixing of (1) a mixture of a transition metal compound such as a tetraalkoxy titanium compound with a non-metallic oxygen-containing compound such as an alcohol and (2) a strongly reducing alkylating agent such as a dialkyl magnesium compound are useful in the preparation of catalysts for polymerizing α-olefins at ultra-high efficiencies at high polymerization temperatures.

BACKGROUND OF THE INVENTION

This invention relates to precursors for and to new catalystcompositions useful for initiating and promoting polymerization ofα-olefins and to a polymerization process employing such catalystcompositions.

It is well known that olefins such as ethylene, propylene and 1-butene,in the presence of metallic catalysts, particularly the reactionproducts of organometallic compounds and transition metal compounds, canbe polymerized to form substantially unbranched polymers of relativelyhigh molecular weight. Typically such polymerizations are carried out atrelatively low temperatures and pressures.

Among the methods of producing such linear olefin polymers, some of themost widely utilized are those described by Professor Karl Ziegler inU.S. Pat. No. 3,113,115 and 3,257,332. In these methods, the catalystemployed is obtained by admixing a compound of a transition metal ofGroups IVB, VB, VIB and VIII of Mendeleev's Periodic Table of Elementswith an organometallic compound. Generally, the halides, oxyhalides andalkoxides or esters of titanium, vanadium and zirconium are the mostwidely used transition metal compounds. Common examples of theorganometallic compounds include the hydrides, alkyls and haloalkyls ofaluminum, alkylaluminum halides, Grignard reagents, alkali metalaluminum hydrides, alkali metal borohydrides, alkali metal hydrides,alkaline earth metal hydrides and the like. Usually, polymerization iscarried out in a reaction medium comprising an inert organic liquid,e.g. an aliphatic hydrocarbon, and the aforementioned catalyst. One ormore olefins may be brought into contact with the reaction medium in anysuitable manner. A molecular weight regulator, which is normallyhydrogen, is usually present in the reaction vessel in order to suppressthe formation of undesirable high molecular weight polymers.

Following polymerization, it is common to remove catalyst residues fromthe polymer by repeatedly treating the polymer with alcohol or otherdeactivating agent such as aqueous base. Such catalyst deactivationand/or removal procedures are expensive both in time and materialconsumed as well as the equipment required to carry out such treatment.

Furthermore, most of the aformentioned known catalyst systems are moreefficient in preparing polyolefins in slurry (i.e., wherein the polymeris not dissolved in the carrier) than in solution (i.e., wherein thetemperature is high enough to solubilize the polymer in the carrier).The lower efficiencies of such catalysts in solution polymerization isbelieved to be caused by the general tendency of such catalysts tobecome rapidly depleted or deactivated by the significantly highertemperatures that are normally employed in solution processes. Inaddition, processes involving the copolymerization of ethylene withhigher α-olefins exhibit catalyst efficiencies significantly lower thanethylene homopolymerization processes.

Recently, catalysts having higher efficiencies have been disclosed,e.g., U.S. Pat. No. 3,392,159, U.S. Pat. No. 3,737,393, West Germanpatent application No. 2,231,982 and British Pat. Nos. 1,305,610 and1,358,437. While the increased efficiencies achieved by using theserecent catalysts are significant, even higher efficiencies aredesirable, particularly in copolymerization processes.

More recently, e.g. British Pat. No. 1,492,379, high efficiencycatalysts have been employed which permit polymerization temperaturesabove 140° C. Such high polymerization temperatures provide for reducedenergy requirements in solution polymerization processes in that thecloser the polymerization temperature is to the boiling point of thepolymerization solvent, the less energy is required in removing thesolvent.

Even more recently, e.g. U.S. Pat. No. 4,250,286 and U.S. Pat. No.4,269,733, the preparation of a catalyst for polymerizing olefins hasbeen disclosed in which the catalyst contains the product resulting fromthe admixture of a transition metal compound and a zinc compound.

In copending applications Ser. No. 313,868 filed Oct. 22, 1981 and313,867 filed Oct. 22, 1981 we have disclosed a similar catalyst systemfor the polymerization of olefins in which the catalyst contains theproduct resulting from the admixture of a transition metal compound anda strongly reducing metal alkyl such as trialkyl aluminum or dialkylmagnesium.

We have now discovered that such catalyst can be improved if thetransition metal compound is first mixed with an oxygen-containingmaterial before addition of the strongly reducing metal alkyl compound.The catalysts subsequently prepared therefrom have higher initial ratesof reaction and higher efficiencies than do those catalysts preparedwithout the oxygen-containing material.

SUMMARY OF THE INVENTION

The present invention in one aspect is a transition metal-containingcomponent suitable for use in the preparation of olefin polymerizationcatalysts which is the reaction product or complex formed by mixing at atemperature and for a time sufficient to provide a color change

(1) the reaction product or complex formed by mixing

(a) a transition metal compound having at least one hydrocarbyloxy groupattached to said transition metal and

(b) a non-metallic oxygen-containing component; with

(2) a reducing alkylating agent containing a metal

wherein the atomic ratio of the metal contained in component (2) totransition metal (Tm) is from about 0.1:1 to about 5:1, preferably fromabout 0.2:1 to about 3:1 and most preferably from about 0.25:1 to about2:1; and the oxygen-containing component is employed in quantities so asto provide an atomic ratio of O(oxygen):Tm of from about 0.1:1 to about4:1, preferably from about 0.2:1 to about 3:1 and most preferably fromabout 0.4:1 to about 2:1.

Another aspect of the present invention are catalysts for polymerizingα-olefins which comprise the catalytic reaction product of

(A) the aforementioned reaction product or complex;

(B) a magnesium halide resulting from the reaction of (a) anorganomagnesium component and (b) a halide source; and

(C) an organoaluminum compound, if required.

The components are employed in quantities which provide the compositionwith atomic ratios of the elements as follows:

Mg:Tm is from about 1:1 to about 200:1, preferably from about 2:1 toabout 100:1, most preferably from about 5:1 to about 75:1.

Al:Tm is from about 0.1:1 to about 200:1, preferably from about 0.5:1 toabout 100:1 and most preferably from about 1:1 to about 75:1.

Excess X:Al is from about 0.0005:1 to about 5:1, preferably from about0.002:1 to about 2:1 and most preferably from about 0.01:1 to about1.4:1.

Excess X is the amount of halide above that amount which istheoretically required to convert the organomagnesium component tomagnesium dihalide.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is most advantageously practiced in apolymerization process wherein an α-olefin is polymerized, generally inthe presence of hydrogen as a molecular weight control agent, in apolymerization zone containing an inert diluent and the catalyticreaction product as hereinbefore described. Especially advantageous isthe copolymerization of ethylene and higher α-olefins using thecatalytic reaction product of this invention. The foregoingpolymerization process is most beneficially carried out under relativelylow temperature and pressure (as compared to classical high pressurefree radical techniques), although very high pressures are optionallyemployed.

Olefins which are suitably homopolymerized or copolymerized in thepractice of this invention are generally the aliphatic α-monoolefins orα-diolefins having from 2 to 18 carbon atoms. Illustratively, suchα-olefins can include ethylene, propylene, butene-1, pentene-1,3-methylbutene-1, 4-methylpentene-1, hexene-1, octane-1, dodecene-1,octadecene-1, 1,7-octadiene, 1,4-hexadiene, mixtures thereof and thelike. It is understood that α-olefins may be copolymerized with otherα-olefins and/or with small amounts, i.e., up to about 25 weight percentbased on the polymer, of other ethylenically unsaturated monomers suchas styrene, α-methylstyrene and similar ethylenically unsaturatedmonomers which do not destroy conventional Ziegler catalysts. Mostbenefits are realized in the polymerization of aliphatic α-monoolefins,particularly ethylene and mixtures of ethylene with up to 50, especiallyfrom about 0.1 to about 40, weight percent of propylene, butene-1,hexene-1, octene-1, 4-methylpentene-1, 1,7-octadiene, 1,4-hexadiene orsimilar α-olefin or diolefin based on total monomer.

Suitable reducing alkylating agents which can be employed in the presentinvention include one or more of those represented by the empiricalformula M'R_(a-b) X_(b) wherein M' is a metal selected from the groupconsisting of Al, B, Mg, or Li; X is a halogen, preferably chlorine orbromine; each R is independently an alkyl group having from 1 to about20 carbon atoms, preferably from about 1 to about 10 carbon atoms andmost preferably from about 1 to about 4 carbon atoms; a has a valueequal to the valance of metal M' and b has a value of from zero to thevalue of a minus one (a minus 1).

Suitable aluminum compounds which can be employed herein as a reducingalkylating agent include one or more of those represented by theempirical formulae R₃ Al, R₂ AlX or RAlX₂, wherein R and X are ashereinbefore defined. Particularly suitable aluminum compounds includetriethyl aluminum, trimethyl aluminum, diethylaluminum chloride,ethylaluminum dichloride, mixtures thereof and the like.

Suitable magnesium compounds which can be employed herein as a reducingalkylating agent include one or more of those represented by theempirical formulae R₂ Mg or RMgX, wherein R and X are as hereinbeforedefined. Particularly suitable compounds include, for example, butylethyl magnesium, n-butyl sec-butyl magnesium, di-n-hexyl magnesium,ethyl magnesium chloride, mixtures thereof and the like.

Suitable boron compounds which can be employed herein as a reducingalkylating agent include one or more of those represented by theempirical formulae BR₃, BR₂ X or BRX₂ wherein R and X are ashereinbefore defined. Particularly suitable compounds include, forexample, triethyl boron and ethyl boron dichloride, mixtures thereof andthe like.

Suitable lithium compounds which can be employed herein as a reducingalkylating agent include one or more of those represented by theempirical formula LiR wherein R and X are as hereinbefore defined.Particularly suitable compounds include, for example, n-butyl lithium,sec-butyl lithium, mixtures thereof and the like.

Suitable non-metallic oxygen-containing compounds which can be employedherein include, for example, molecular oxygen, air, alcohols, ketones,aldehydes, carboxylic acids, esters of carboxylic acids, peroxides,water and the like. Those compounds which are soluble in hydrocarbonsolvent are especially preferred.

Particularly suitable alcohols include, for example, methanol, ethanol,n-butanol, sec-butanol, mixtures thereof and the like.

Particularly suitable ketones which can be employed herein include, forexample, acetone, methyl ethyl ketone, methyl isobutyl ketone, mixturesthereof and the like.

Particularly suitable carboxylic acids which can be employed hereininclude, for example, formic acid, acetic acid, stearic acid, mixturesthereof and the like.

Particularly suitable esters of carboxylic acids which can be employedherein include, for example ethyl acetate, methyl formate, ethyloxalate, mixtures thereof and the like.

Particularly suitable ethers which can be employed include, for example,diethyl ether, ethyl vinyl ether, mixtures thereof and the like.

Particularly suitable aldehydes which can be employed herein include,for example, formaldehyde, acetaldehyde, propionaldehyde, mixturesthereof and the like.

Particularly suitable peroxides which can be employed herein include,for example, hydrogen peroxide, t-butylperoxide, mixtures thereof andthe like.

Suitable transition metal compounds which can be employed in the presentinvention include those represented by the empirical formulae Tm(OR)_(y)X_(x-y), Tm(OR)_(x-2) O or TmOX_(x-2), wherein Tm is a transition metalselected from groups IVB, VB or VIB; each R is independently ahydrocarbyl group, preferably alkyl or aryl, having from 1 to 20,preferably from 1 to about 10, carbon atoms; each X is independently ahalogen, preferably chlorine or bromine; x has a value equal to thevalence of Tm and y has a value from 1 to the valence of Tm.

Particularly suitable transition metal compounds include, for example,tetraethoxy titanium, tetraisopropoxy titanium, tetra-n-butoxy titanium,di-n-butoxy titanium dichloride, tetraphenoxy titanium, tetra-n-propoxytitanium, tetra-(2-ethylhexoxy) titanium, tri-n-butyoxy vanadium oxide,oxyvanadium trichloride, tri-isopropoxy vanadium oxide, zirconiumtetra-n-butoxide, zirconium tetra-n-propoxide, zirconiumtetra-isopropoxide, mixtures thereof and the like.

Suitable organomagnesium components which can be employed in the presentinvention include those represented by the empirical formula a MgR"₂·xMR"_(y) wherein each R" is independently hydrocarbyl orhydrocarbyloxy, M is aluminum, zinc or mixtures thereof and x is aboutzero to about 10, preferably zero to about 5, most preferably from aboutzero to about 2.5, and y denotes the number of hydrocarbyl and/orhydrocarbyloxy groups which corresponds to the valence of M. As usedherein, hydrocarbyl and hydrocarbyloxy are monovalent hydrocarbonradicals. Preferably, hydrocarbyl is alkyl, cycloalkyl, aryl, aralkyl,alkenyl and similar hydrocarbon radicals having 1 to 20 carbon atoms,with alkyl having 1 to 10 carbon atoms being especially preferred.Likewise, preferably, hydrocarbyloxy is alkoxy, cycloalkyloxy, aryloxy,aralkyloxy, alkenyloxy and similar oxyhydrocarbon radicals having 1 to20 carbon atoms, with alkoxy having 1 to 10 carbon atoms beingpreferred. Hydrocarbyl is preferred over hydrocarbyloxy.

Preferably the organomagnesium compound is a hydrocarbon solubledihydrocarbylmagnesium such as the magnesium dialkyls and the magnesiumdiaryls. Exemplary suitable magnesium dialkyls include particularlyn-butyl-sec-butyl magnesium, diisopropyl magnesium, di-n-hexylmagnesium, isopropyl-n-butyl magnesium, ethyl-n-hexyl magnesium,ethyl-n-butyl magnesium, di-n-octyl magnesium and others wherein thealkyl has from 1 to 20 carbon atoms. Exemplary suitable magnesiumdiaryls include diphenylmagnesium, dibenzylmagnesium, andditolylmagnesium. Suitable organomagnesium compounds include alkyl andaryl magnesium alkoxides and aryloxides and aryl and alkyl magnesiumhalides with the halogen-free organomagnesium compounds being moredesirable.

Among the halide sources which can be employed herein are the activenon-metallic halides and metallic halides.

Suitable non-metallic halides are represented by the empirical formulaR'X wherein R' is hydrogen or an active monovalent organic radical and Xis a halogen. Particularly suitable non-metallic halides include, forexample, hydrogen halides and active organic halides such as t-alkylhalides, allyl halides, benzyl halides and other active hydrocarbylhalides wherein hydrocarbyl is as defined hereinbefore. By an activeorganic halide is meant a hydrocarbyl halide that contains a labilehalogen at least as active, i.e., as easily lost to another compound, asthe halogen of sec-butyl chloride, preferably as active as t-butylchloride. In addition to the organic monohalides, it is understood thatorganic dihalides, trihalides and other polyhalides that are active asdefined hereinbefore are also suitably employed. Examples of preferredactive non-metallic halides include hydrogen chloride, hydrogen bromide,t-butyl chloride, t-amyl bromide, allyl chloride, benzyl chloride,crotyl chloride, methylvinyl carbinyl chloride, α-phenylethyl bromide,diphenyl methyl chloride and the like. Most preferred are hydrogenchloride, t-butyl chloride, allyl chloride and benzyl chloride.

Suitable metallic halides which can be employed herein include thoserepresented by the empirical formula MR_(y-a) X_(a) wherein M is a metalof Groups IIIA or IVA, of Mendeleev's Periodic Table of Elements, R is amonovalent organic radical, X is a halogen, y has a value correspondingto the valence of M, and a has a value from 1 to y. A suitable metallichalide is SnCl₄, although the preferred metallic halides are aluminumhalides of the empirical formula A1R_(3-a) X_(a) wherein each R isindependently hydrocarbyl as hereinbefore defined such as alkyl, X is ahalogen, and a is a number from 1 to 3. Most preferred arealkyl-aluminum halides such as ethylaluminum sesquichloride,diethylaluminum chloride, ethylaluminum dichloride, and diethylaluminumbromide, with ethylaluminum dichloride being especially preferred.Alternatively, a metal halide such as aluminum trichloride or acombination of aluminum trichloride with an alkyl aluminum halide or atrialkyl aluminum compound may be suitably employed.

It is understood that the organic moieties of the aforementionedorganomagnesium, e.g., R", and the organic moieties of the halidesource, e.g., R and R', are suitably any other organic radical providedthat they do not contain functional groups that poison conventionalZiegler catalysts. Preferably such organic moieties do not containactive hydrogen, i.e., those sufficiently active to react with theZerewitinoff reagent.

In preparing the reaction product or complex of the present invention,the transition metal component and oxygen-containing component are mixedtogether in a suitable inert solvent or diluent followed by the additionof the alkylating agent in a quantity and under suitable conditions soas to effect a color change in the reaction mixture. Suitable conditionsinclude temperatures of from about -50° C. to about 110° C., preferablyfrom about 0° C. to about 30° C. At lower temperatures, longer times maybe required to effect a color change.

The reaction time is also affected by the concentration of thereactants, e.g. low concentrations require longer times at any giventemperature than do higher concentrations. The solvents which can beemployed include those suitable for preparing the catalysts of thisinvention with the hydrocarbon solvents being most suitable.

Sufficient quantities of the alkylating agent should be employed whenpreparing the reaction complex so as to provide the desired color changebut less than any such quantity which would result in substantialreduction of the transition metal component.

The color change which occurs upon addition of the essentiallynon-reducing alkylating agent varies depending upon the particularcomponents employed, i.e., the particular oxygen-containing compoundand/or the particular alkylating agent.

The magnesium halide can be preformed from the organomagnesium compoundand the halide source or it can be prepared in situ in which instancethe catalyst is prepared by mixing in a suitable solvent (1) theorganomagnesium component, (2) the halide source and (3) the reactionproduct or complex formed by mixing (a) a mixture of (i) said transitionmetal component and (ii) said oxygen-containing component and (b) saidalkylating agent.

The foregoing catalyst components are combined in proportions sufficientto provide atomic ratios as previously mentioned.

In cases wherein neither the organomagnesium component, the halidesource nor the alkylating agent contains aluminum or contains aninsufficient quantity of aluminum, it is necessary to include in thetotal catalyst an aluminum compound such as an alkyl aluminum compound,e.g., a trialkyl aluminum, an alkyl aluminum halide or an aluminumhalide. If polymerization temperatures below 180° C. are employed, theatomic ratios of Al:Ti may be from about 0.1:1 to about 200:1,preferably from 0.5:1 to about 100:1. However, when polymerizationtemperatures above 180° C. are employed, the aluminum compound is usedin proportions such that the Mg:Al ratio is more than 0.3:1, preferablyfrom 0.5:1 to 10:1, and Al:Ti ratio is less than 120:1, preferably lessthan 75:1. It is understood, however, that the use of very low amountsof aluminum necessitates the use of high purity solvents or diluents inthe polymerization zone. Further, other components present in the zoneshould be essentially free of impurities which react with aluminumalkyls. Otherwise, additional quantities of an organometallic compoundas previously described, preferably an organoaluminum compound, must beused to react with such impurities. Moreover, it is understood that inthe catalyst the aluminum compound should be in the form of trialkylaluminum or alkyl aluminum halide provided that the alkyl aluminumhalide be substantially free of alkyl aluminum dihalide. In the abovementioned aluminum compounds, the alkyl groups independently have from 1to about 20, preferably from 1 to about 10, carbon atoms.

When additional quantities of aluminum compound are employed, it can beadded to the aforementioned catalyst during the preparation thereof orthe aluminum deficient catalyst can be mixed with the appropriatealuminum compound prior to entry into the polymerization reactor or,alternatively, the aluminum deficient catalyst and the aluminum compoundcan be added to the polymerization reactor as separate streams oradditions.

The foregoin catalytic reaction is preferably carried out in thepresence of an inert diluent. The concentrations of catalyst componentsare preferably such that when the essential components of the catalyticreaction product are combined, the resultant slurry is from about 0.005to about 1.0 molar (moles/liter) with respect to magnesium. By way of anexample of suitable inert organic diluents can be mentioned liquifiedethane, propane, isobutane, n-butane, n-hexane, the various isomerichexanes, isooctane, paraffinic mixtures of alkanes having from 8 to 12carbon atoms, cyclohexane, methylcyclopentane, dimethylcyclohexane,dodecane, industrial solvents composed of saturated or aromatichydrocarbons such as kerosene, naphthas, etc., especially when freed ofany olefin compounds and other impurities, and especially those havingboiling points in the range from about -50° to about 200° C. Alsoincluded as suitable inert diluents are benzene, toluene, ethylbenzene,cumene, decalin and the like.

Mixing of the catalyst components to provide the desired catalyticreaction product is advantageously carried out under an inert atmospheresuch as nitrogen, argon or other inert gas at temperatures in the rangefrom about -100° to about 200° C., preferably from about 0° to about100° C. The period of mixing is not considered to be critical as it isfound that a sufficient catalyst composition most often occurs withinabout 1 minute or less. In the preparation of the catalytic reactionproduct, it is not necessary to separate hydrocarbon soluble componentsfrom hydrocarbon insoluble components of the reaction product.

In order to maximize catalyst efficiency, the catalyst is prepared bymixing the components of the catalyst in an inert liquid diluent in thefollowing order: organomagnesium compound, halide source, the aluminumcompound if required, and the reaction product or complex formed fromsaid transition metal compound, oxygen-containing compound andalkylating agent.

In the polymerization process employing the aforementioned catalyticreaction product, polymerization is effected by adding a catalyticamount of the above catalyst composition to a polymerization zonecontaining at least one α-olefin monomer, or vice versa. Thepolymerization zone is maintained at temperatures in the range fromabout 0° to about 300° C. preferably at solution polymerizationtemperatures, e.g., from about 130° to about 250° C., for a residencetime of about a few seconds to several days, preferably 15 seconds to 2hours. It is generally desirable to carry out the polymerization in theabsence of moisture and oxygen and a catalytic amount of the catalyticreaction product is generally within the range from about 0.0001 toabout 0.1 millimoles titanium per liter of diluent. It is understood,however, that the most advantageous catalyst concentration will dependupon polymerization conditions such as temperature, pressure, solventand presence of catalyst poisons and that the foregoing range is givento obtain maximum catalyst yields in weight of polymer per unit weightof titanium. Generally, in the polymerization process, a carrier whichmay be an inert organic diluent or solvent or excess monomer isemployed. In order to realize the full benefit of the high efficiencycatalyst of the present invention, care must be taken to avoidoversaturation of the sollvent with polymer. If such saturation occursbefore the catalyst becomes depleted, the full efficiency of thecatalyst is not realized. For best results, it is preferred that theamount of polymer in the carrier not exceed about 50 weight percentbased on the total weight of the reaction mixture.

It is understood that inert diluents employed in the polymerizationrecipe are suitably as defined hereinbefore.

The polymerization pressures preferably employed are relatively low,e.g., from about 50 to about 1000 psig, especially from about 100 toabout 700 psig. However, polymerization within the scope of the presentinvention can occur at pressures from atmospheric up to pressuresdetermined by the capabilities of the polymerization equipment. Duringpolymerization it is desirable to stir the polymerization recipe toobtain better temperature control and to maintain uniform polymerizationmixtures throughout the polymerization zone.

In order to optimize catalyst yields in the polymerization of ethylene,it is preferable to maintain an ethylene concentration in the solvent inthe range of from about 1 to about 10 weight percent, mostadvantageously from about 1.2 to about 2 weight percent. To achievethis, when an excess of ethylene is fed into the system, a portion ofthe ethylene can be vented.

Hydrogen can be employed in the practice of this invention to controlthe molecular weight of the resultant polymer. For the purpose of thisinvention, it is beneficial to employ hydrogen in concentrations rangingfrom about 0.001 to about 1 mole per mole of monomer. The larger amountsof hydrogen within this range are found to produce generally lowermolecular weight polymers. It is understood that hydrogen can be addedwith a monomer stream to the polymerization vessel or separately addedto the vessel before, during or after addition of the monomer to thepolymerization vessel, but during or before the addition of thecatalyst.

The monomer or mixture of monomers is contacted with the catalyticreaction product in any conventional manner, preferably by bringing thecatalytic reaction product and monomer together with intimate agitationprovided by suitable stirring or other means. Agitation can be continuedduring polymerization, or in some instances, the polymerization can beallowed to remain unstirred while the polymerization takes place. In thecase of more rapid reactions with more active catalysts, means can beprovided for refluxing monomer and solvent, if any of the latter ispresent, in order to remove the heat of reaction. In any event, adequatemeans should be provided for dissipating the exothermic heat ofpolymerization. If desired, the monomer can be brought in the vaporphase into contact with the catalytic reaction product, in the presenceor absence of liquid material. The polymerization can be effected in thebatch manner, or in a continuous manner, such as, for example, bypassing the reaction mixture through an elongated reaction tube which iscontacted externally with suitable cooling media to maintain the desiredreaction temperature, or by passing the reaction mixture through anequilibrium overflow reactor or a series of the same.

The polymer is readily recovered from the polymerization mixture bydriving off unreacted monomer and solvent if any is employed. No furtherremoval of impurities is required. Thus, a significant advantage of thepresent invention is the elimination of the catalyst residue removalsteps. In some instances, however, it may be desirable to add a smallamount of a catalyst deactivating reagent of the types conventionallyemployed for deactivating Ziegler catalysts. The resultant polymer isfound to contain insignificant amounts of catalyst residue.

The following examples are given to illustrate the invention, and shouldnot be construed as limiting its scope. All percentages are by weightand all parts are by molar or atomic ratio unless otherwise indicated.

In the following examples, the melt index values I₂ and I₁₀ weredetermined by ASTM D 1238-70 and the density values were determined byASTM D 1248.

EXAMPLES 1-8 AND COMPARATIVE EXPERIMENTS A-D A. Preparation of theTitanium Complexes

All titanium.alcohol.reducing alkylating agent complexes were preparedby simple admixture of the neat tetraisopropyl titanate (TiPT) with theneat n-butanol (n-BuOH), followed by addition of a 15% solution of thereducing alkylating agent in ISOPAR® E (an isoparaffinic hydrocarbonfraction havig a boiling range of 116° C.-134° C.). After development ofa color change (generally within ˜30 minutes if at all), the mixture wasdiluted to give an overall titanium concentration of 0.025 molar. Thecomplexes were then used in catalyst preparations. The components andcolor of the complexes are given in the following Table I.

                  TABLE I                                                         ______________________________________                                        EXAMPLE  MOLE RATIO OF                                                        OR COMP. TiPT/nBuOH/                                                          EXPT. NO.                                                                              METAL ALKYL    COLOR OF COMPLEX                                      ______________________________________                                        C.E. A   1/0/0.25.sup.1 Dark green with solids                                Ex. 1    1/0.5/0.25.sup.1                                                                             Green with solids                                     Ex. 2    1/1/0.25.sup.1 Lt. green with solids                                 C.E. B   1/5/0.25.sup.1 Pale green with solids                                C.E. C   1/0/0.5.sup.2  Green                                                 Ex. 3    1/0.5/0.5.sup.2                                                                              Green                                                 Ex. 4    1/1/0.5.sup.2  Lt. green                                             Ex. 5    1/2/0.5.sup.2  Clear                                                 C.E. D   1/0/1          Lt. brown                                             Ex. 6    1/0.5/1        Clear                                                 Ex. 7    1/1/1          Clear                                                 Ex. 8    1/2/1          Clear                                                 ______________________________________                                         .sup.1 nbutyl-sec-butyl magnesium                                             .sup.2 triethyl aluminum                                                      .sup.3 ethyl aluminum chloride                                           

B. Preparation of the Catalyst

In a 4-oz., narrow mouth catalyst bottle under an inert atmosphere wasmixed the following components in the following order:

    ______________________________________                                        97.80    ml of ISOPAR® E                                                  0.85     ml of 0.703 M n-butyl-sec-butyl magnesium                            0.75     ml of 1.00 M ethyl aluminum dichloride                               0.60     ml of 0.025 M titanium complex                                       100.00   ml                                                                   ______________________________________                                    

C. Polymerization

Into a stirred one-gallon batch reactor was added 2 liters of ISOPAR® E,4 psig of hydrogen, 175 psig of ethylene, and 10 ml (0.0015 mmole Ti) ofthe previous described catalysts. Total pressure was kept constant at200 psig using ethylene (the solvent vapor pressure being 21 psig) andthe reactor temperature was controlled at 150° C. Because of the highinitial activities of these catalysts, an initial exotherm is produced,the size of which is dependent on catalyst activity (the higher theexotherm, the higher the initial catalyst activity). This exotherm canbe controlled to some extent by cooling the reactor with large volumesof air blown past the reactor. Total reaction time was 30 minutes.Catalyst efficiencies and exotherms are listed in Table II. The exampleand comparative experiment numbers correspond to those in Table 1, forthe various complexes prepared.

Each example shows an improvement in the catalyst as evidenced byincreased catalyst activity (increased exotherm) and increased catalystefficiency. The amount of improvement in highly dependent on the amountof O-containing compound or metal alkyl used. Generally, an optimumlevel of O-compound and metal alkyl is found, above or below whichcatalyst efficiencies are not optimized. Too high a level of O-compound(C.E. B) or metal alkyl may lead to lower catalyst efficiencies than ifneither compound were used.

                  TABLE II                                                        ______________________________________                                        EXAMPLE                                                                       OR COMP.  EXOTHERM    CATALYST EFFICIENCY                                     EXPT. NO. TEMP. °C.                                                                          #PE/#Ti                                                 ______________________________________                                        C.E. A    18          2.297 × 10.sup.6                                  Ex. 1     20          2.298 × 10.sup.6                                  Ex. 2     19          2.439 × 10.sup.6                                  C.E. B    18          2.182 × 10.sup.6                                  C.E. C    18          2.210 × 10.sup.6                                  Ex. 3     23          2.305 × 10.sup.6                                  Ex. 4     24          2.495 × 10.sup.6                                  Ex. 5     19          2.223 × 10.sup.6                                  C.E. D    17          1.966 × 10.sup.6                                  Ex. 6     18          2.419 × 10.sup.6                                  Ex. 7     18          2.151 × 10.sup.6                                  Ex. 8     21          2.184 × 10.sup.6                                  ______________________________________                                    

We clam:
 1. A reaction product or complex formed from an admixture of(a)a reaction product or complex formed from a mixture of(i) at least onetransition metal compound represented by the empirical formulaeTm(OR)_(v) X_(x-y), TmOX_(x-2) or Tm(OR)_(x-2) O wherein Tm is atransition metal selected from groups IVB, VB or VIB; each R isindependently a hydrocarbyl group having from 1 to about 20 carbonatoms; each X is independently a halogen; x has a value equal to thevalence of Tm and y has a value from 1 to the valence of Tm; and (ii) atleast one non-metallic oxygen-containing compound selected from thegroup consisting of molecular oxygen, air, alcohols, ketones, aldehydes,carboxylic acids, esters of carboxylic acids, peroxides, water andmixtures thereof; and wherein said mixture of (i) and (ii) is subjectedto a temperature of from about -50° C. to about 110° C. for a timesufficient to effect a color change; and (b) a reducing alkylating agentrepresented by the empirical formula M'R_(a-b) X_(b) wherein M' is ametal selected from the group consisting of Al, Li, Mg or B; X is ahalogen, preferably chlorine or bromine; each R is independently analkyl group having from 1 to about 20 carbon atoms; a has a value equalto the valence of the metal M' and b has a value of from zero up to thevalence of the metal M' minus 1; and wherein components (a) and (b) aremixed in proportions such that the atomic ratio of M':Tm is from about0.1:1 to about 5:1 and the atomic ratio of O:Tm is from about 0.1:1 toabout 4:1.
 2. A reaction product or complex of claim 1 wherein incomponent (a) Tm is titanium, each R is independently a hydrocarbylgroup having from 2 to about 10 carbon atoms and X is chlorine orbromine; and said oxygen-containing component is an alcohol; incomponent (b), M' is Al, R is a hydrocarbyl group having from 1 to about10 carbon atoms; the M':Ti atomic ratio is from about 0.2:1 to about3:1; and the O:Ti atomic ratio is from about 0.2:1 to about 3:1.
 3. Areaction product or complex of claim 1 wherein in component (a) R is asaturated aliphatic hydrocarbyl group and the M':Ti ratio is from about0.25:1 to about 2:1; and the O:Ti atomic ratio is from about 0.4:1 toabout 2:1.
 4. A reaction product or complex of claims 1, 2, or 3 whereincomponent (a-i) is titanium tetraethoxide, titanium tetra-n-propoxide,titanium tetra-isopropoxide, titanium tetra-n-butoxide, titaniumtetra-(2-ethylhexoxide) or mixture thereof; component (a-ii) isn-butanol, sec-butanol, n-propanol, isopropanol, water, acetone ormixture thereof; and component (b) is triethyl aluminum, ethyl aluminumdichloride, diethylaluminum chloride, triethyl boron, butyl ethylmagnesium, or mixture thereof.
 5. A catalytic reaction product of(A) areaction product or complex formed from the admixture of(1) the reactionproduct or complex formed by mixing (a) at least one transition metalcompound represented by the empirical formulae Tm(OR)_(y) X_(x-y),TmOX_(x-2) or Tm(OR)_(x-2) O wherein Tm is a transition metal selectedfrom groups IVB, VB or VIB; each R is independently a hydrocarbyl group,having from 1 to about 20 carbon atoms; each X is independently ahalogen; x has a value equal to the valence of Tm and y has a value from1 to the valence of Tm; and(b) at least one oxygen-containing compoundselected from the group consisting of molecular oxygen, air, alcohols,ketones, aldehydes, carboxylic acids, esters of carboxylic acids,peroxides, water and mixtures thereof; and wherein said mixture of (i)and (ii) is subjected to a temperature of from about -50° C. to about110° C. for a time sufficient to effect a color change; and (2) at leastone reducing alkylating agent represented by the empirical formulaM'R_(a-b) X_(b) wherein M' is a metal selected from the group consistingof Al, B, Mg or Li; X is a halogen, preferably chlorine or bromine; eachR is independently an alkyl group having from 1 to about 20 carbonatoms; a has a value equal to the valence of metal M' and b has a valueof from zero up to the valence of the metal M' minus 1; (B) a magnesiumhalide resulting from the reaction of(1) an organomagnesium compoundrepresented by the empirical formula MgR"₂.xMR"_(y) wherein M isaluminum or zinc, each R" is independently a hydrocarbyl orhydrocarbyloxy group having from 1 to about 20 carbon atoms, x has avalue from zero to 10 and y has a value corresponding to the valence ofM; with (2) a halide source selected from(a) an active non-metallichalide, said non-metallic halide corresponding to the empirical formulaR'X wherein R' is hydrogen or a hydrocarbyl group such that thehydrocarbyl halide is at least as active as sec-butyl chloride and doesnot poison the catalyst and X is halogen or (b) a metallic halidecorresponding to the empirical formula MR_(y-a) X_(a) wherein M is ametal of Group IIIA or IVA of Mendeleev's Periodic Table of Elements, Ris a monovalent hydrocarbyl radical, X is halogen, y is a numbercorresponding to the valence of M and a is a number of 1 to y; and (C)when the organomagnesium component and/or the halide source providesinsufficient quantities of aluminum, an aluminum compound is added whichis represented by the empirical formula AlR_(y') X_(y") wherein R and Xare as defined above and y' and y" each have a value of from zero tothree with the sum of y' and y" being three; andwherein the componentsare employed in quantities which provide an atomic ratio of the elementsMg:Tm of from about 1:1 to about 200:1; M':Tm of from about 0.1:1 toabout 5:1; O:Tm of from about 0.1:1 to about 4:1; Al:Tm of from about0.1:1 to about 200:1 and an excess X:Al of from about 0.0005:1 to about5:1.
 6. A catalytic reaction product of claim 5 wherein(a) in component(A-1), Tm is titanium, each R is independently a hydrocarbyl grouphaving from 1 to about 10 carbon atoms and Xis chlorine or bromine andsaid oxygen-containing component is an alcohol; (b) in component (A-2),M' is Al, R is a hydrocarbyl group having from 1 to about 10 carbonatoms; (c) in component (B-1), M is aluminum and R" is a hydrocarbylgroup having from 1 to about 10 carbon atoms and x has a value of fromabout zero to about 5; (d) in component (B-2-A), R' is hydrogen or atertiary butyl group and X is chlorine; (e) in component (B-2-b), M is ametal from Groups IIIA or IVA, y-a is zero, 1 or 2 and X is chlorine;(f) in component (C), the aluminum compound is a trialkyl aluminumcompound wherein the alkyl groups independently have from 1 to about 10carbon atoms; and (g) the components are employed in quantities so as toprovide atomic ratios of Mg:Ti of from about 2:1 to about 100:1; M':Tifrom about 0.2:1 to about 3:1; O:Ti of from about 0.2:1 to about 3:1;Al:Ti of from about 0.5:1 to about 100:1 and excess X:Al of from about0.002:1 to about 2:1.
 7. A catalytic reaction product of claim 6wherein(a) in component (A-1), R is a saturated aliphatic hydrocarbylgroup; (b) in component (B-1), x has a value of from about 0.15 to about2.5; and (c) the components are employed in quantities so as to provideatomic ratios of Mg:Ti of from about 5:1 to about 75:1; M':Ti of fromabout 0.25:1 to about 2:1; Al:Ti of from about 1:1 to about 75:1; O:Tiof from about 0.5:1 to about 2:1; Al:Ti of from about 1:1 to about 75:1and excess X:Al of from about 0.01:1 to about 1.4:1.
 8. A catalyticreaction product of claim 7 wherein(a) component (A-1-a) is titaniumtetraethoxide, titanium tetra-n-propoxide, titanium tetra-isopropoxide,titanium tetra-n-butoxide, titanium tetra-(2-ethylhexoxide) or a mixturethereof; (b) component (A-1-b) is n-butanol, sec-butanol, n-propanol,isopropanol, water, acetone or a mixture thereof; (c) component (A-2) istriethylaluminum, ethylaluminum dichloride, diethylaluminum chloride,triethyl boron, butyl ethyl magnesium or a mixture thereof; (d)component (B-1) is a dialkyl magnesium compound wherein the alkyl groupsindependently have from 1 to about 10 carbon atoms; and (e) component(B-2) is substantially anhydrous hydrogen chloride, ethyl aluminumdichloride or tin tetrachloride.
 9. A catalytic reaction product ofclaims 5, 6, 7 or 8 wherein the components are added in the order (B-1),(B-2), (C) if employed and (A).
 10. A catalytic reaction product ofclaims 5, 6, 7 or 8 wherein the components are added in the order (B-1),(B-2), (A) and (C) if employed, and provided that the halide source,(B-2), is not a tin compound.
 11. A catalytic reaction product of claims5, 6, 7 or 8 wherein the components are added in the order (B-2), (C) ifemployed, (B-1) and (A).
 12. In a catalyst composition comprising amagnesium halide, a transition metal compound and a reducing alkylatingcompound, said composition having an atomic or molar ratio of theelements Mg:Tm of from about 1:1 to about 200:1; reducing alkylatingcompound:Tm of from about 0.1:1 to about 5:1; Al:Tm of from about 0.1:1to about 200:1 and an excess X:Al of from about 0.0005:1 to about 5:1;the improvement which comprises forming a reaction product or complex of(1) a mixture of (i) the transition metal compound and (ii) aoxygen-containing compound selected from the group consisting ofmolecular oxygen, air, alcohols, ketones, aldehydes, carboxylic acids,esters of carboxylic acids, peroxides, water and mixtures thereof; andwherein said mixture of (i) and (ii) is subjected to a temperature offrom about -50° C. to about 110° C. for a time sufficient to effect acolor change; and in quantities so as to provide an atomic ratio of O:Tmof from about 0.1:1 to about 4:1; and (2) the reducing alkylatingcompound prior to preparation of the catalyst therefrom.
 13. A catalystcomposition of claim 12 wherein the atomic ratios of the elements areMg:Tm of from about 2:1 to about 100:1; reducing alkylating compound:Tmof from about 0.2:1 to about 3:1; O:Tm of from about 0.2:1 to about 3:1;Al:Tm of from about 0.5:1 to about 100:1 and excess X:Al of from about0.002:1 to about 2:1.
 14. A catalyst composition of claim 13 wherein theatomic ratios of the elements are Mg:Tm of from about 5:1 to about 75:1;reducing alkylating compound:Tm of from about 0.25:1 to about 2:1; O:Tmof from about 0.4:1 to about 2:1; Al:Tm of from about 1:1 to about 75:1and excess X:Al of from about 0.01:1 to about 1.4:1.
 15. A catalystcomposition of claims 12, 13 or 14 wherein said reducing alkylatingcompound is represented by the empirical formula AlR_(3-x) X_(x) whereinR is a hydrocarbyl group having from 1 to about 10 carbon atoms, X is ahalogen and x has a value of zero, 1 or
 2. 16. A catalytic reactionproduct of claims 12, 13 or 14 wherein said transition metal compound isa titanium compound.
 17. A catalytic reaction product of claim 16wherein(a) said titanium compound is titanium tetraethoxide, titaniumtetra-n-propoxide, titanium tetra-n-butoxide, titaniumtetra-(2-ethylhexoxide) or a mixture thereof; (b) said oxygen-containingcompound is n-butanol, sec-butanol, n-propanol, isopropanol, water,acetone or a mixture thereof; and (c) said reducing alkylating compoundis triethylaluminum, ethylaluminum dichloride, diethylaluminum chloride,triethyl boron, butyl ethyl magnesium or a mixture thereof.